"When you go there, you quickly see that these people are extremely poor, isolated, without electricity, without education, and without access to medical care. They're living the way they've lived for thousands of years."

Fares Howari is a professor of geology at the United Arab Emirates University in Al Ain who was not involved with the report.

"The United Nations has declared this area one of the world's greatest environmental disasters," Howari said.

Richardson and Hussain's report, he said, "is a very interesting article trying to document the recovery process of these marshes."

Eden Again

Restoration efforts have made some progress in revitalizing the region, as noted by the new data Richardson and Hussain collected.

In 2003 local farmers began blowing up dikes and earthen dams to release water back into the marshes.

Within a year of reflooding, species recovery began. Small invertebrates, fish, and bird species all began returning, though in much reduced numbers.

Rare bird species like the marbled teal and the Basrah reed warbler, thought close to extinction, apparently survived the wetlands' destructionboth were spotted in a 2005 census.

Within two years about 39 percent of the destroyed marshes had standing water, and vegetation was growing at a rate of 300 square miles (800 square kilometers) a year.

Recent overflows of the Tigris and Euphrates rivers are probably responsible for replenishing the marshes with even more seeds, insect larvae, and fish stocks, encouraging more birds to return, the report authors say.

Salinity in the three presently restored marshes seems to be at levels that will sustain freshwater fish. Analysis of the surface water shows no detectable pesticides or other pollutants.

Joy Zedler, a restoration ecologist at the University of Wisconsin in Madison who was not involved in the paper, is optimistic about the marshes' rehabilitation.

Zedler served on the Eden Again International Technical Advisory Panel, an international group of experts organized by the nonprofit Iraq Foundation to respond to the environmental disaster.

Cautious hope for the marshes' recovery turned to optimism "when people took charge and changed water flows that replenished desiccated wetlands far faster than we imagined possible," Zedler said.

"Perhaps we will never know what happened throughout these vast tortured lands. But we will have a glimpse of positive change and the hope that sufficient water of sufficient quality will sustain regional biodiversity."

Updating Agriculture

Not all the news is so promising. Reflooded soils are releasing toxins, such as hydrogen sulfide, from military ordnance. Land mines are littered throughout the marshes.

Also, report co-author Richardson says, vast areas of the marshes cannot be sustained as humans move back in unless new agricultural methods are adopted.

"Water usage is going up," he said, "and there will be a shortage, for sure, especially in the drought years.

"That's primarily true because the agricultural practices are ancient. They just pour water over the desert, which mostly evaporates and destroys the soil.

"They have to use modern drip agriculture, as they do in Saudi Arabia and Israel, because you can't afford to lose all that water. But that takes money, training, equipment."

Richardson is hopeful that the situation will improve, especially now that new government projects are underway.

"There have been training courses, putting in modern crops like alfalfa, training the farmers, bringing in new seed sources, improving animal husbandry," he said.

"But the amount of money [being spent on marsh restoration] is less than a hundred million [U.S.] dollars compared to hundreds of billions we've spent on the war and reconstruction."

Still, the progress so far, Richardson says, has been substantial. Restoration of significant portions of the marshes, though not all of them, is certainly within reach.

"It's come back so far, so quickly. I call it the miracle in the marsh."